1. Field of the Invention
The present disclosure relates to methods for the synthesis of zinc oxide (ZnO) nanostructures, such as nanorods, nanoneedles, and nanowires.
2. Description of the Related Art
Semiconductor nanostructures have attracted significant interest due to their novel physical and chemical properties, which depend on their size, shape and morphology. Lately, attention has been focused on the materials chemistry of one-dimensional (1D) semiconductor oxides. The wide band gap (around 3.37 eV) and large excitonic binding energy (about 60 meV) make ZnO a good candidate for a variety of applications, such as room temperature UV lasers, light-emitting diodes, solar cells, sensors, thin-film transistor, and varistors. Also the optical and electronic properties of ZnO can be simultaneously controlled by varying the shape, dimension and uniformity of the nanostructures.
Several methods, for example, molecular beam epitaxy, thermal evaporation, vapor-liquid-solid growth, laser-ablation methods, chemical vapor deposition, metal organic chemical vapor deposition, hydrothermal methods, solvothermal methods, and electrochemical deposition have been developed to prepare ZnO nanostructures. Certain techniques typically require high pressure and longer reaction times (e.g., several days). Other methods require complex procedures, high costs, sophisticated instrumentation and rigid conditions.